/Engine/Source/Runtime/GeometryCore/Public/CompGeom/ConvexDecomposition3.h
Merge the pairs of convex hulls in the decomposition that will least increase the error. Intermediate results can be used across merges, so it is best to do all merges in one call. Note: A future version of this function may replace NumOutputHulls with MaxOutputHulls, but this version keeps both parameters for compatibility / consistent behavior.
The number of merges performed
int32 MergeBest ( int32 TargetNumParts, double ErrorTolerance, double MinThicknessTolerance, bool bAllowCompact, bool bRequireHullTriangles, int MaxOutputHulls, const [FSphereCovering](API\Runtime\GeometryCore\CompGeom\FSphereCovering) * OptionalNegativeSpace, const FTransform * OptionalTransformIntoNegativeSpace )